he B-24 Liberator was famous for mincing japanese fighters. Each bomber had TEN M2 machine guns. A formation of four or more was considered impregnable by the japs.
Evidently, the Luftwaffe missed that memo. Never heard that before. The Japanese were starting to do a bit of a number on the B-29s until Iwo.
Fighter Escort is(was) the difference.
I think that most of the B-29s that served in the Pacific had their defensive weapons removed to save weight and extend their range.